BWI is a focus city for Southwest Airlines, and is the second largest airport by number of departures for that airline after Chicago–Midway.[6] With a 71% market share in 2014,[7] BWI is also a fortress hub for Southwest. A record 23.8 million passengers traveled through BWI in 2015, an increase of 6.8% over the previous year.[8] BWI was the 23rd busiest airport in North America and the 75th busiest airport in the world in 2014 by number of passengers.[9]

In 2010 BWI was ranked as the best airport of its size (15–25 mil. passengers) in the world by the Airports Council International based on its 2009 Airport Service Quality survey.[10] The airport also won second place for North American airports in the "Best Food and Beverage Program" of the 2010 Richard A. Griesbach Excellence in Airport Concessions Contest, sponsored by the Airports Council International.[11]

Planning for a new airport on 3,200 acres (1,300 ha) to serve the Baltimore/Washington area began just before the end of World War II. In 1944, the Baltimore Aviation Commission decided the best location to build a new airport would be near Linthicum Heights.[12] The State Aviation Commission approved as well,[13] the land was purchased near Friendship Methodist Church in 1946,[14] and ground was broken in 1947.[15] Located in Anne Arundel County, Maryland next to the site where Friendship Methodist Church stood until 1948,[16]

The first phase of the airport's modernization was completed in 1974 at a cost of $30 million. Upgrades included improved instrument landing capabilities and runway systems, and construction of three new air cargo terminals, expanding the airport's freight capacity to 2.53 acres (1.02 ha).[21]

The passenger terminal renovation program was complete in 1979, the most dramatic work of the airport's modernization, which was designed by DMJM along with Peterson & Brickbauer.[22] The BWI terminal more than doubled in size to 14.58 acres (5.90 ha); the number of gate positions increased from 20 to 27. The total cost was $70 million. To continue the work, the BWI Development Council was established to support initiatives for airport development.[21]

In the first half of the 1990s, runway 15L/33R was extended 1,800 feet from 3,199 feet (550 m from 975 m) to its current length of 5,000 ft (1,500 m), allowing it to be used for smaller passenger jets like the Boeing 737.

Beginning in the 1980s and later for much of the 1990s, BWI was a major hub for Piedmont Airlines and successor US Airways, but that airline's financial difficulties in the wake of the dot-com bust, the September 11 attacks, and intense low fare competition forced it to reduce its presence at the airport. The airport has been a major haven for low-cost flights in the Baltimore/Washington Metropolitan Area since Southwest Airlines' arrival in September 1993[26] and subsequent expansion in the early 2000s. Southwest is the airport's largest carrier, accounting for 56.12% of passengers carried in 2011.[27]Southwest Airlines currently serves on average 245 daily departures to destinations in the US, Mexico and the Caribbean.

To accommodate Southwest's extensive presence at the airport, in 2005 Concourses A and B were expanded, renovated, and integrated with one another to house all of that airline's operations there. This new facility, designed by URS Corporation, opened on May 22, 2005. On October 1 of that year, the airport was renamed again, to Baltimore-Washington International Thurgood Marshall Airport, to honor the former US Supreme Courtjustice, who grew up in Baltimore.[28][29]

On Aug 5, 2014, little-used runway 04-22 was permanently closed.[30] It was only 6,000 feet long and used primarily when the main runways needed to be closed for repairs. The last operation on the runway was a Southwest Airlines flight from Chicago Midway that arrived at 4:18 AM.[31]

In late 2008, Health magazine named BWI the second healthiest airport in the United States.[32] In 2009 the airport had a six percent increase in air travelers due to the proliferation of discount flights.[33] In a 2009 survey of airport service quality by Airports Council International, BWI was the world's top ranking airport in the 15-to-25-million-passenger category.[34] BWI also ranked seventh, in medium-sized airports, based on customer satisfaction conducted by J.D Power and Associates.[35]

In early 2016, a partnership between the airport and Towson University's WTMD Radio Station announced a new concert series that will take place at the terminal's baggage claim on the lower level.[36] The local bands of Wye Oak, Arboretum, and Super City. This new series follows the release event of Animal Collective's new album Painting With on November 25, 2015, where the new album was streamed throughout the airport.

Baltimore/Washington International Thurgood Marshall Airport has five concourses, though Concourses A and B were essentially merged into a single concourse in the renovations completed in 2005.[28] The Maryland Aviation Administration has its headquarters on the third floor of the terminal building.[37]

Concourse E has 5 gates: E1, E3, E4, E6, and E8.
Officially known as the Governor William Donald Schaefer International Terminal, it serves British Airways, Condor, Norwegian Air Shuttle, Southwest Airlines (international arrivals that are not pre-cleared) and WOW Air. All international arrivals from non-pre-cleared destinations and all charter airlines are handled at Concourse E. The Air Mobility Command has a post in Concourse E flying active service troops out to worldwide destinations.

Currently improvements are being made to widen concourse C. Concourse C will be given the level of amenities found at the A and B concourses in approximately 8,500 square feet (790 m2; 0.20 acres) of new food and retail space. On April 30, 2013, the airport opened the new concourse C security checkpoint, with nine security lanes, the most at the airport, as well as a new concourse A/B-C connector.[39]

The Federal Aviation Administration is currently in the process of designing a new air traffic control tower that will replace the current tower.[40] The new tower is estimated to cost between $21 million and $26 million and be 228 ft (69 m) tall.[41] There is no estimated start date.

On July 12, 2013, BWI Airport and the Maryland Aviation Administration launched a 3-year, $125-million construction project. This project will include modernizing concourse D, a new airside connection linking concourse D and E, and the new configuration of the concourses will allow 2 gates on concourse D to serve both domestic and international flights. The project is scheduled to begin in late 2014, with an estimated completion date of fall 2016.[41]

With winds from the north or west, aircraft will generally land on runway 33L and depart on runway 28. When the winds are from the south or east, arrivals are on runway 10 and departures are on runway 15R. Use of the smaller parallel runway (33R/15L) is restricted to smaller propeller-driven aircraft and small corporate jets. The largest planes that land at BWI regularly are Boeing 757s, McDonnell Douglas MD-11s, and Boeing 767s. Because of the many cargo and charter operations at BWI, it is common to see one or two Boeing 747s or Airbus A330s on a daily basis as well. Runway 10/28 was closed for a 60-day period that began on August 20, 2012 to update and implement safety requirements for Runway Safety Areas established by the Federal Aviation Administration.[48]

For the 12-month period ending December 31, 2011, the airport had 276,133 aircraft operations, an average of 757 per day: 93% air carrier, 6% general aviation and less than 1% military operations. In 2009, there were 75 aircraft based at the airport: 45 single engine, 19 multi-engine, and 11 jets.[49]

As of January 2014, Southwest Airlines, including its subsidiary AirTran Airways, represents approximately 71% of passengers followed by Delta Air Lines at 8%.

In August 2014, BWI launched a new bicycle sharing system with the Boston-based company Zagster.[59] Located adjacent to the BWI Airport Light Rail Station, the bike sharing service connects terminal passangers to the nearby BWI Trail, as well as other local destinations.[60]

In 1985, the BWI Business District was established as a way to formalize businesses and hotels operating adjacent to the airport. The district comprises two smaller districts located to the north (West Nursery Hotel District) and west (Stoney Run District) of the airport. Numerous traveler resources and employment centers are located within both districts, such as the BWI Rail Station and BWI Rental Car Facility in the Stoney Run District, and the BWI Business District Light Rail Station, the NSAFriendship Annex, and dozens of hotel facilities in the West Nursery District.

In the early 1990s, BWI Airport opened the Thomas A. Dixon Aircraft Observation Area at Friendship Park. The observation plaza features a playground and a terrace overlooking the southern approach to the airport's 15R-33L runway.[61] From this vantage point, several planes can be viewed simultaneously as they prepare for landing. The southern loop of the 13.3 mile BWI Trail travels through the park, providing cyclist and pedestrian access to the park.